[PYTHON] Dynamically generate sqlalchemy filter according to the conditions

Overview

I saw the following implementation using sqlalchemy. It is a method that only makes the difference between narrowing down from the passed user list or narrowing down from the entire table. (Other conditions are exactly the same) I thought that it would be better to make it common when considering the correction, so I investigated the solution.

def get_specified_age_users_from_user_list(user_name_list={}, age):
    """
Get users of a specific age among the specified users from the User table
    """
    users = session.query(User).\
        filter(users.age==age).\
        filter(users.name.in_(user_name_list)).\
        all()
    return users

def get_specified_age_users(age):
    """
Get users of a specific age from the User table
    """
    users = session.query(User).\
        filter(users.age==age).\
        all()
    return users

solution

Pass the condition in tuple format to the ʻand_` method.

from sqlalchemy import and_

def get_specified_age_users(user_name_list={}, age):
    filters = []
    #Add condition only if arguments are passed
    if user_name_list:
        filters.append(User.name.in_(user_name_list))
    # and_The argument of is tuple because it needs to be tuple
    users = session.query(User).\
        filter(and_(*filters)).\
        all()
    return users

#SQL to be executed
##If specified
SELECT omitted
FROM users 
WHERE users.name IN (%s)

##If not specified
SELECT omitted
FROM users